Circular irrigation system with worm gear drive

ABSTRACT

A worm gear drive assembly for driving the wheeled support assemblies for an elongated irrigation pipe including a motor having an output controlled in response to bending or deflection of the pipe and a forwardly and rearwardly extending shaft with a drive worm gear on each end thereof engaged with a worm wheel for driving the supporting wheels. Each supporting wheel is connected to the frame structure in such a manner that it may be oriented for driving the pipe in a direction transverse to the longitudinal axis thereof or in a position perpendicular thereto to enable the irrigation pipe to be towed or pulled in a direction parallel to its longitudinal axis to facilitate movement from one area to be irrigated to another.

This application discloses improvements in the drive mechanism for thesupporting assemblies of an irrigation pipe as disclosed in copendingapplication Ser. No. 792,013, filed Jan. 17, 1969, .Iadd.now U.S. Pat.No. 3,608,826.Iaddend. for Electrically Driven Circular IrrigationSystem.

The present invention generally relates to drive supporting assembly foran elevated irrigation pipe for supporting and driving the irrigationpipe for movement in a direction transverse of the longitudinal axis ofthe irrigation pipe and more particularly includes a worm gear drive forthe supporting wheels on the supporting assembly.

An object of the present invention is to provide a worm gear drive forthe supporting wheels at the forward and rearward ends of a supportingframe or assembly for an elongated irrigation pipe in which the pipe issupported by a plurality of similar support assemblies with each supportassembly including a drive motor having a forward and rearward outputshaft with the forward and rearward ends of the output shaft having aworm shaft thereon in meshing engagement with a worm wheel carried bythe hub of the wheel to rotate the wheel thus driving the supportassembly.

Another object of the invention is to provide a support assembly inwhich the wheels at the opposite ends thereof are orientated with therotational axes thereof in parallel relation to each other and generallyparallel to the longitudinal axis of the irrigation pipe supportedthereby for moving the pipe in a direction transverse to itslongitudinal axis with the wheels also being positioned for rotationabout a substantially coincidental rotational axis in perpendicularrelation to the longitudinal axis of the pipe so that the irrigationpipe may be towed longitudinally from one area to another such as fromone field to another through a relatively narrow gate or along arelatively narrow road or the like thus facilitating movement of theirrigation system from one area to another.

A further important object of the present invention is to provide asupport assembly for irrigation pipes having a worm gear drive toprovide positive control of the driven wheels so that they will not rollfreely forward in the event of traversing uneven terrain therebyproviding positive control of the driving speed of the wheels at alltimes.

Another object of the present invention resides in its simplicity ofconstruction, dependability and relatively inexpensive manufacturing andmaintenance cost.

These together with other objects and advantages which will becomesubsequently apparent reside in the details of construction andoperation as more fully hereinafter described and claimed, referencebeing had to the accompanying drawings forming a part hereof, whereinlike numerals refer to like parts throughout, and in which:

FIG. 1 is a perspective view of one of the supporting assemblies for theirrigation pipe illustrating the orientation of the components thereof.

FIG. 2 is a plan view of the supporting assembly of the presentinvention illustrating the drive motor, output shaft extending forwardlyand rearwardly therefrom in the position of a driving wheel when theyare drivingly supporting the irrigation pipe.

FIG. 3 is a longitudinal, vertical sectional view taken substantiallyupon a plane passing along section line 3--3 of FIG. 2 illustratingfurther structural details of the invention.

FIG. 4 is a detailed sectional view taken substantially upon a planepassing along section line 4--4 of FIG. 3 illustrating furtherstructural details of the drive mechanism.

FIG. 5 is a detail sectional view, on an enlarged scale, takensubstantially upon a plane passing along section line 5--5 of FIG. 1illustrating the structure of the wheel and worm gear drive associatedtherewith.

FIG. 6 is an elevational view illustrating the positioning of thesupporting wheel perpendicular to the end of the support assembly tosupport the irrigation pipe for movement axially along its longitudinalaxis.

FIG. 7 is an exploded group perspective view of the wheel-mountingassembly.

Referring now specifically to the drawings, the supporting assembly forthe irrigation system is generally designated by the numeral 10 and theirrigation pipe or boom is generally designated by the numeral 12 withthe structure of the irrigation pipe or boom being the same as thatdisclosed in Ser. No. 792,013 mentioned previously. The irrigation boomor pipe is in the form of an elongated tubular pipe 14 having aplurality of sprinklers 16 mounted longitudinally therealong togetherwith bracing and supporting truss assemblies generally designated by thenumeral 18 all of which are the same as disclosed in Ser. No. 792,013.The support assembly 10 includes a generally A-shaped constructionformed by a pair of downwardly converging frame members 20 and 22 whichextend both forwardly and rearwardly from the pipe 14 as illustrated inFIG. 1. The lower ends of the members 20 and 22 are interconnected by arigid plate 24 which in turn is rigidly fixed to the horizontallydisposed tubular frame member 26 as by welding or the like with theplate 24 being disposed at the same angle as the members 20 and 22 andsecured rigidly thereto by bolt-type fasteners 28 or the like. The upperends of the members 20 and 22 are secured to the pipe 14 by suitablebracket structures generally designated by the numeral 30 and thesupport members 22 have a control system 32 having a conductor 34depending therefrom for operating the electric drive motor 36. All ofthis construction is the same as the structure disclosed in Ser. No.792,013 including the flexible coupling 38 in the pipe 14 and theflanged coupling 40 therein provided with an O-ring seal in which bothof the flanges of the flange coupling coupling 40 have a groovereceiving an O-ring seal. The control system for controlling theoperation of the electric motor in response to deflection of adjacentpipe sections about an axis defined by a specific construction of theflexible coupling 38 is the same as and specifically disclosed in Ser.No. 792,013.

The improvement disclosed in this application is directed toward thedrive connection between the electric motor and a pair of supportingwheels 42 and 44 which are located at the opposite ends of the supportframe member 26. Each wheel assembly 42 and 44 includes a pneumaticallyinflated tire 46 supported on a conventional wheel rim 48 secured inplace on a hub 50 by lug bolts 52 to enable conventional vehicularwheels to be employed.

The hub 50 includes a tubular extension 54 supporting spaced bearingassemblies 56 which engage the tapered spindle shaft 58 to journal thehub 50 from the spindle 58 in a well known and conventional manner. Thebearing assemblies 56 are retained in position by a retaining nut 60 anda grease cap or seal 62 is attached to the tubular extension 54 toretain lubrication within the hub assembly. This structure issubstantially conventional in vehicular structures in that thestationary spindle 58 rotatably journals the hub 50 and the wheelassembly for rotation about the axis of the spindle 58.

The spindle shaft 58 extends inwardly into an attaching end portion 64which extends under a channel-shaped plate 68 being welded thereto asillustrated in FIGS. 5 and 7. The channel-shaped member 68 has dependingflanges along each side edge thereof and an upstanding end lug 69 andupstanding side lugs 71 telescoped over and engaged with achannel-shaped plate 70 secured to the frame member 26 as by welding orthe like. A through-bolt 72 extends through the channel-shaped member68, the channel-shaped member 70 as well as the frame member 26 and atorque plate 73 welded to the frame member 26 thus securing thesecomponents in rigid relation with the spindle or shaft 58 secured inperpendicular relation to the longitudinal axis of the frame member 26.

Attached to the inner surface of the hub 50 is an adapter plate 74 whichis secured to the hub by the lug bolts 52 and which has a worm wheel 76secured to the inner surface thereof by suitable countersunk bolts 78 orthe like so that the worm wheel 76 adapter plate 74, hub 50, wheel 48and pneumatic tire 46 will all rotate together with the periphery of theworm wheel .[.46.]. .Iadd.76 .Iaddend.having the usual worm wheel teeth80 formed thereon.

In meshing engagement with the worm wheel 76 is a drive worm shaft orgear 82 engaging the upper edge of the worm wheel 76 with the rotationalaxis of the worm gear 82 being perpendicular to the rotational axis ofthe worm wheel 76 in a well known and conventional manner. The worm gearor pinion 82 is journalled in an upward extension 84 of an annularhousing 86 which also journals the worm wheel and which includes aremovable side plate 87 secured in place by suitable fastening bolts.One end of the worm gear projects from the housing extension 84 and isprovided with a universal coupling 88 thereon. A drive shaft 90 isconnected to the universal coupling 88 adjacent the worm wheel housing86 and the inner end of the drive shaft 90 is provided with a universalcoupling 92 thereon. As illustrated in FIG. 2, the electric motor 36 issubstantially disposed centrally of the frame member 26 with the driveshaft structure being identical toward both drive wheels. The electricmotor 36 is provided with a reduction gear assembly 94 thereon havingforwardly and rearwardly extending output shafts 96 connected with theuniversal couplings 92 to enable driving rotation to be imparted to theshafts 90 at the same speed for rotating the wheels 42 and 44 at thesame rotational speed.

The upper end of the extension 84 on the housing 86 is engaged with thetorque plate 73 which extends into overlying relation thereto by a pairof upstanding lugs 98 on housing extension 84. Thus, the through-bolt 72secures the housing 86 and extension 84 in place with the lugs on thehousing transmitting torque to the torque plate 73 and the frame member26.

The electric motor and its reduction gear 94 may be supported from avertical plate 104 rigidly secured to the frame member 26 which may benotched out for receiving the plate 104 which may be welded in positionthereon. Also, a forwardly extending and curved guard rod 106 isprovided for each of the wheels with the rod being secured to the inneredge of the channel-shaped member 68 by any suitable fastening structureor the like.

The plate 73 is rigidly fixed between the pair of lugs 98 on the housingextension 84 and serves as a torque plate for preventing the housing 86and its extension 84 as well as the worm shaft 82 from rotating due tothe torque exerted on the wheel. When it is desired to tow theirrigation pipe from one field to another, it is only necessary toloosen or remove the bolt 72 sufficient to enable the lugs 69 and 71 topass under member 70 to enable pivoting of the spindle 58 and itsassociated structure including the worm wheel, worm pinion and housingtherefor to a position whereby the spindle 58 is parallel with thelongitudinal axis of the frame member 26. The bolt 72 is then tightened.[.wit.]. .Iadd.with .Iaddend.member 70 disposed between lug 69 and theinner end edges of lugs 71 thus providing rigid lock for the spindle 58in both of its positions. The universal coupling .[.86.]. .Iadd.88.Iaddend.is detached from the drive shaft 90 prior to such movement.FIG. 6 illustrates the towed position and in this position, all of thesupporting wheels 42 and 44 may be oriented with their axis of rotationbeing perpendicular to the longitudinal axis of the pipe 14 so that thepipe 14 may then be towed in a direction parallel with this longitudinalaxis thus enabling the irrigation system to be moved from one field toanother through a gate opening in a fence, along a relatively narrowroad or the like without disassembly and reassembly of the irrigationpipe. When the wheel is in the position of FIG. 6, the worm wheelhousing may rotate with the wheel which enables the worm pinion 82 torotate with the worm wheel 76. If desired, the drive shaft components 90may be telescopic or detachably connected to the universal couplings inany suitable manner and if desired, the universal coupling 88 may bedetached from the worm wheel 82 to eliminate any possible damage theretowhen the wheel has been oriented in the position of FIG. 6.

Any suitable bearing support structure may be provided for the wheelwith the structure illustrated enabling conventional vehicularcomponents to be employed thereby enabling the use of conventional andcommercially available components to retain the cost of the device aslow as possible.

The foregoing is considered as illustrative only of the principles ofthe invention. Further, since numerous modifications and changes willreadily occur to those skilled in the art, it is not desired to limitthe invention to the exact construction and operation shown anddescribed, and accordingly all suitable modifications and equivalentsmay be resorted to, falling within the scope of the invention asclaimed.

I claim:
 1. In an irrigation system having a boom movable over arelatively large land area and including an elongated pipe receivingwater for discharge through a plurality of sprinkler heads, thatimprovement comprises a plurality of support assemblies for the boom,each support assembly including an elongated frame member generally inperpendicular relation to the boom, a wheel journalled at each end ofthe elongated frame member for engaging the ground surface, a drivemotor supported from the frame member, and a driving connection betweensaid motor and .[.each of.]. said wheels for driving the wheels andpropelling the support assembly thus propelling the elongated boom, saiddrive connection including a worm pinion and worm wheel to providepositive driving connection between the motor and wheels to prevent freewheeling of the wheels in the event of traversal of a downgrade, eachwheel including a spindle, means connecting the spindle to the framemember, a wheel hub journalled on said spindle, a wheel .[.and pneumatictire.]. secured to the hub, said worm wheel being secured to said hubfor rotation therewith .Iadd.about a common axis.Iaddend. wherebyrotation of the worm wheel will drivingly rotate the wheel.Iadd., saidmeans connecting the spindle to the frame means including means enablingthe spindle to pivot approximately 90° whereby the axes of rotation ofthe wheels may be parallel to the axis of the boom or perpendicularthereto, and means disengaging the drive connection between the motorand wheels to enable the boom to be towed..Iaddend.
 2. The structure asdefined in claim 1 wherein said driving connection includes an elongateddrive shaft extending from the motor, and extending toward each of thewheels, a worm pinion engaged with each worm wheel and drivinglyconnected to the outer ends of said shaft.
 3. The structure as definedin claim 2 wherein said worm pinions are detachably connected to thedrive shaft with the worm pinion and worm wheel being disposed in ahousing, means connecting the housing and the frame member to preventrotation of the housing and enable torque to be exerted on the wormwheel and wheel connected therewith for driving the wheel.
 4. Thestructure as defined in claim 3 wherein said means connecting thespindle to the frame member includes releasable fastening means toretain the spindle in a position substantially perpendicular to theframe member for rotation of the wheels about axes substantiallyparallel to the longitudinal axis of the elongated boom and orientationof the spindle in a transport position for orientating the wheels in atransport position having rotational axes substantially perpendicular tothe longitudinal axis of the elongated boom thereby enabling theelongated boom to be towed axially when all of the wheels on all of thesupporting assemblies have been oriented in the transport positionthereby enabling the irrigation system to be moved from one area beingirrigated to another without disassembly and reassembly of thecomponents of the irrigation system.
 5. The structure as defined inclaim 4 together with a curved guard rod extending outwardly from meansconnecting the spindle to the frame member and curving in front of thewheel to protect the wheel and deflect crops from out of the path of thewheel.
 6. The structure as defined in claim 4 wherein the detachableconnection between the drive shaft and worm pinion is automaticallydisconnected when the means connecting the housing and frame member isdisconnected and the wheel is disposed in transport position to enablefree wheeling of the wheel and rotation of the housing therewith.
 7. Inan irrigation system having a boom movable over a relatively large landarea and including an elongated pipe receiving water for dischargethrough a plurality of sprinkler heads, a plurality of supportassemblies for the boom, each support assembly including an elongatedframe member generally in perpendicular relation to the boom, a wheeljournalled at each end of the elongated frame member for engaging theground surface, a drive motor, that improvement comprising a worm driveconnection between the drive motor and a ground-engaging wheel toprovide positive drive for the wheel and prevent free-wheeling of thewheel when traversing a downgrade, said worm drive connection includinga worm wheel connected with the ground-engaging wheel, and a worm pinionmeshing with the worm wheel and drivingly connected with the motor, andmeans disengaging the drive connection between the drive motor and.[.ground-engaging wheel.]. .Iadd.worm pinion.Iaddend. to enable towingof the boom when moving the irrigation system from one area to another..Iadd.
 8. The structure as defined in claim 7 wherein each of saidwheels includes a supporting member defining an axis of rotation for thewheel, and means mounting the supporting member from the frame memberfor pivotal movement between a boom towing position in which the axis ofrotation is perpendicular to the boom and a position in which the axisis parallel to the boom for movement of the boom in a circular path, andmeans releasably securing said supporting member in bothpositions..Iaddend..Iadd.
 9. The structure as defined in claim 7 whereinsaid supporting member includes a housing for the worm drive connection,and means securing the housing to the frame member for orientation inboth positions..Iaddend..Iadd.
 10. In an irrigation system, an elongatedwater distribution pipe, a plurality of support means supportnig saidpipe, each of said support means comprising an elongated, horizontallydisposed frame means which is disposed transversely to the longitudinalaxis of said pipe, a wheel assembly at each end of said frame means,power means including a drive shaft drivingly connected to at least oneof said wheel assemblies, the rotational axis of each of said wheelassemblies being generally parallel to the longitudinal axis of saidpipe when distributing water, and means for selectively pivoting saidwheel assemblies with respect to the frame means to a tow position sothat the rotational axis of each of said wheel assemblies will betransversely disposed with respect to the longitudinal axis of said pipeto permit said pipe and said support means to be towed, said drivenwheel assembly comprising a drive wheel, a gear housing having gearmeans therein connected with a positive drive output member, said drivewheel being mounted on said output member for rotation therewith, andmeans for disengaging the drive shaft from the gear means so that saiddrive wheel may freely rotate when said wheel assembly has been pivotedto said tow position..Iaddend. .Iadd.
 11. The structure as defined inclaim 10 wherein said gear housing includes a plate disposedhorizontally thereon, said frame means including a plate disposedhorizontally thereon, said means for selectively pivoting said wheelassemblies includes pivot bolt means extending through said plates, andlug means interengaging said plates to retain the plates in twoperpendicular positions about the pivot bolt for retaining the wheelassemblies in water distributing position and tow position.